Clip for card clothing strips

ABSTRACT

The invention relates to fastening means (in particular to so called clothing clips) for the fastening of clothing strips on flat rods, made of light metal or light metal alloys. Thereby the fastening means are laid-out in such a manner that, when the flat rods assume their operating temperature, these are not deformed.

[0001] The present invention relates to fastening means, in particularto positive connecting means, as for example clips for fastening ofclothing strips to flat rods.

[0002] Modern textile processing machines, to which belong cards inparticular, said cards are applied, depending on the process stage,within the machine are furnished with different carding segments. To thecarding segments of the card belong the stationary carding segmentsand/or carding rods, in particular, in the pre-carding and re-cardingzone and the carding segments in the flat, the so-called stationary flatrods or the revolving flat rods. Most cards nowadays are furnished withrevolving flat aggregates, i.e. they possess revolving flat rods. Cardswith stationary flats and respective stationary flat rods are lesscommon. With cards it is nowadays common to furnish the flat orrevolving flat rods with so-called clothing strips. The clothing stripsare furnished with flexible or semi-rigid clothing, which differ fromall steel clothing and/or saw tooth type clothing in such a way, thatthey are inserted and/or punched individually, or as U-shaped doublehooks in strip form, into more or less flexible fabric and plasticlayers.

[0003] The clothing strips are attached with fastening means, so-calledclips or clothing strip clips, to the carding rods of the cardingsegments. Various clips of the state of the art are shown for example inthe disclosures U.S. Pat. No. 5,755,012, U.S. Pat. No. 5,898,978 and DE513728. Such an arrangement is for example also shown in FIG. 1. Theclips 1 are made of sheet metal and/or steel and they have the advantagethat they simplify the fastening and replacing of the clothing strips 2onto the flat rods 3. The clips 1 have the function, to fixedly clampthe clothing strips 2 onto the flat rods. They do this, by establishinga positive connection between the clothing strip and the flat rod.Normally the clips are employed in pairs, so that on both sides of theflat rod such a clip each ensures for respective clamping, see FIG. 1.On one side the clips have teeth 4, these are inserted and/or punchedinto the clothing strips 2 (illustrated in FIG. 1 with a broken line).Thereby these teeth are positively connected with the clothing strip.The other side 5 of the clips is pressed around the rib 6 of the flatrod 3 applying a suitable tool. Thus the clips 1 firmly clamp theclothing strips 2 to the flat rod 3 over its entire length. This type offastening has proved successful in the past. The clips can be attachedvery easily to the flat rods with a suitable tool and can also be easilyremoved again.

[0004] The carding rods and in particular the flat rods for the cardwere formerly manufactured in the form of a—usually T-shaped—cast iron.Recently they have also been manufactured in the form of hollow profiles(extruded profiles) of light metal and/or light metal alloys (e.g. flatrod 3 in FIG. 1). As a material for the production aluminium is oftenused. The carding segments co-operate with rotary rollers, as do theflat rods, which co-operate with the cylinder of the card. Thereby thecarding rods or flat rods must be somewhat longer than the working widthof the card, so that they can rest on the adjustable flex bends on theleft and on the right side of the cylinder and that they can betransported (or in the case of stationary flat rods be fastenedthereon). The flat rods are exposed to a relatively high mechanical load(shearing load) applied trough their carding work. Therefore they musthave a high stability or rigidity, in order not to deflect or deformduring operation.

[0005] The carding quality and thus the quality of the produced card webdepends substantially on the set carding gap (space between the clothingof the flat rods and the clothing of the cylinders). This carding gap isnowadays adjusted within the range of tenth of millimetres. Usually itmeasures between 0.2 and 0.3 mm, depending on the processed fibrematerial and the desired carding quality. It can be observed that thetendency in the spinning mills points in the direction of settingadjusting the carding gap within ever more narrow ranges. Carding gapsettings of 0.15 mm represent at the present the rather extreme case,however, such narrow settings might be wished in the future morefrequently by spinning mills. Therefore the accurate setting of thecarding gap is very important. It is therefore understood, thatfluctuations and inaccuracies in the adjusted space have considerablenegative effects on the quality of the carding process. For the cardingprocess it is very important that the carding gap, over the entire workarea within which carding work is done, can be adjusted evenly i.e. thecarding gap must be accurately adjusted over the total length of theflat rods and over the whole area of the flat (i.e. within the work areaof all flat rods being arranged one behind the other). The narrowerhowever the carding gap is chosen, the more difficult it is to adjust itand to keep it constant. The narrower the range gets within which thecarding gap is to be kept, the more sensitive reacts the flat area, withthe set carding gap, to each effect and to each change, like for exampletemperature fluctuations. The carding gap is adjusted and/or checkedduring standstill with a feeler gauge. Usually this setting takes placeonce in each case after each adjustment of the flats of the card, forexample after maintenance (the replacement of the flats) or in the caseof a change of the processed material (fibre material to be treatednewly often requires another carding gap adjustment). Adjusting of theflats actually always takes place on the “cold machine”, i.e. at normalambient temperature, which can differ, depending on the location of saidmachine the spinning mill, between 20 and 30 degrees Celsius. Duringoperation of the card the operating temperatures at the flat rods,depending on the air conditioning, can amount to between 20 degreesCelsius (during starting period of the machine) and 40 degrees Celsius(with a warm machine and bad air conditioning within the spinning mill).It is understood that the carding gap, even with such temperaturefluctuations, is always to be held at the desired value. However, thenarrower the carding gap needs to be adjusted, the more sensitive is thereactions of the carding process to changes of said gap.

[0006] Recently the flat rods have been made of light metal, inparticular of aluminium, and/or of light metal alloys as extruded hollowprofiles, produced by extrusion method (see FIG. 1). Such flat rods areprovided with solid headpieces at their two ends. Examples of such flatrods can be seen in the disclosures DE 43 04 148 A1, EP 627,507 B1 orU.S. Pat. No. 4,827,573. The headpieces are usually positively connectedwith the aluminium profile and have a machined bearing surface, whichslides accurately and with low friction on the sliding guides of thecard (flex bends). In the case of revolving flat rods the headpieces arefurthermore connected with the drive components of the flat aggregate,e.g. with a driving chain or a driving belt. This design has a number ofadvantages in comparison to the older type flat rods made as casting. Inparticular they can be manufactured more simply and cheaper.

[0007] The use of light metal or light metal alloys as material for theflat rods can, however,—under certain operating conditions—also havedisadvantages. With such types of flat rods up to now common type clipsmade of sheet metal or steel were used. Measurements now revealed thatthese flat rods can deform when the temperature rises to the operatingtemperature in the card. Reason: The clips are mounted onto the flatrods at room temperature. In the case of a temperature rise of the cardto the operating temperature the mounted flat rods resume a concave typeof shape seen in their longitudinal direction, so that the carding gapis larger in the center of the flat rod than at its ends. Thus thecarding process can thus be impaired. The impairment of the cardingprocess is the more serious the narrower the carding gap is set and thelonger the flat rods are. With the carding gap settings applied nowadaysit should therefore be avoided that the flat rods become bent.

[0008] The task of the present invention is thus to avoid thedeformation of the flat rods.

[0009] The invention

[0010] The task is solved by the features of the characteristic parts ofthe independent claims.

[0011] The light metal or the light metal alloy of the flat rods has ahigher coefficient of elongation and/or coefficient of thermal expansionthan the sheet metal and/or the steel from which the clip is made. Thecommercially available clips thus consist of a material (sheet metal orsteel) that has a too high E-modulus for flat rods made of light metal,i.e. they have a low flexibility. They are in particular far lessflexible than the flat rods. In addition, the clips, apart from thematerial properties, also have, due to the design (primarily due to theselected wall thickness), a high rigidity. In the mounted condition theclips have a high clamping force and are, practically seen, inelastic.The wall thickness of commercially available clips amounts to at least0.5 mm. The clothing strips are positively connected (“clipped-on”) ontothe flat rod at room temperature with the help of the clips and asuitable tool. Afterwards the flat rods are examined for their accuracywith regard to the clothing. If necessary the clothing points arereground (by a few hundredths of millimetres), so that the gap betweenthe sliding surfaces of the head pieces of the flat and the area definedby the clothing points resume an accurate predetermined value. Thisexamination is accomplished in the spinning mills at ambient temperatureand is made in order to precisely adjust the carding gap. The flat rodswith the attached clips and clothing strips are subsequently mountedinto the card, at which point they have the ambient temperature. If thecard becomes warm through its operation, then also the flat rodswarm-up, with the consequence that they expand (or try to expand). Theproblem thereby is that the flat rod has, due to the material type(light metal or a respective alloy), a higher coefficient of thermalexpansion than the clip (commercially made of sheet metal or steel).Besides, the clip has, due to the applied material, a high E-modulus(low elasticity) which is additionally reinforced due to its design(wall thickness). The result is a high strength connected with a verylow elasticity (at least a lower elasticity than the flat rod). Thepositive connection of the dips (at least two clips per flat rod arerequired for the fastening) with the flat rod within the area of theribs 6 (see FIG. 1) has a high clamping force. It is so high that norelative motion can take place at these points between the flat rod andthe strip. In particular the material with the higher coefficient ofelongation cannot expand. This has the consequence, that the lowerthermal expansion of the clips prevents the flat rod from expanding,within the clamped section 7, in the same way in longitudinal directionas within the upper non-clamped section 8 of the flat rod, where noobstacle prevents the thermal expansion. The arc-shaped bend of the flatrod resulting from this causes an undesired, non-uniform carding gapover the length of the carding flat. Particularly with narrow settings,where the carding gap is to amount to between 0.2 to 0,15 mm, then thiseffect is particularly negative.

[0012] According to the general idea of the invention it is to beavoided that the flat rod, due to the fastening means, i.e. the clip, isprevented from expanding evenly. This idea can be realised by differentembodiments according to claimed invention.

[0013] According to the first embodiment of the invention the fasteningmeans consists of a material that possesses the same coefficient ofelongation as the flat rod. In a particularly preferred embodiment thefastening means consists thereby also at the same time of the samematerial as the flat rod. According to this embodiment of the inventionit is essential, that light metal flat rods are being used incombination with the fastening means (clothing clips) which, accordingto the invention, comprise the same (or nearly the same) materialcharacteristics.

[0014] This first embodiment according to the invention refers to flatrods that are not manufactured of steel or cast iron. It refers inparticular to flat rods that consist of a light metal or a light metalalloy, in particular of aluminium or an aluminium alloy.

[0015] In a second embodiment according to the invention, fasteningmeans for the fastening of clothing strips on flat rods are used whichconsist of aluminium, or aluminium alloy, or another light metal orlight metal alloy. This second embodiment according to the invention isconcerned with the selection of the material from which the fasteningmeans are made. In a secondary embodiment the flat rods can consist of alight metal or a light metal alloy, in particular they can consist ofaluminium or an aluminium alloy.

[0016] According to a third embodiment of the invention fastening meansfor fastening the clothing strips on flat rods are applied that arecharacterised in that the fastening means are more flexible in theirlongitudinal direction than in their cross direction.

[0017] Such fastening means can have such characteristics due to theirspecific way of design.

[0018] These can be realised in particular in that they are designedwith predetermined weak points. Such predetermined weak points can berealised in such a manner that the fastening means, with regard to theirextension, have different values of elasticity.

[0019] In a fourth embodiment according to the invention, fasteningmeans for fastening the clothing strips on flat rods are applied thathave a wall thickness which is smaller than 0.4 preferably smaller than0,3 mm. By this design measure it is in particular suitable to applywell known materials for the fastening means, for example sheet metal orsteel. Due to the small cross section and/or wall thickness thefastening means, despite an unchanged high E-modulus, is structurallyweakened and therefore less rigid. Thereby, the flat rod is given thepossibility to expand the fastening means, i.e. the clips, inlongitudinal direction. In fact the structural weakening reduces theclamping force of the fastening means, the wall thickness however can beselected in such a manner that the weakening does not critically affectthe clamping force.

[0020] The fifth embodiment according to the invention is characterizedin that between the contact surfaces of the fastening means and the flatrod a sliding means is attached.

[0021] The sliding means is arranged in such a manner, that it permitsthe fastening means, as well as the flat rod, to move and/or expand inlongitudinal direction (i.e. along the flat rod) relative to the otherelement. This relative motion in longitudinal direction takes place inparticular when the temperature of the flat rod rises, so that thecomponent with the higher coefficient of elongation (e.g. the flat rod)can expand unhindered from the other component (e.g. fastening means) inlongitudinal direction. This basically means that the fastening meansdoes not have to take part in this movement or expansion of the flatrod: The flat rod can expand unhindered and thus no tensions candevelop, which could cause a bending of the components. The clampingeffect of the fastening means (transverse to the longitudinal directionof the flat rod) does not become affected.

[0022] In a variation of this fifth embodiment the sliding means betweenthe contact surfaces of fastening means and flat rod is realised as aglide layer with a low coefficient of friction.

[0023] With this embodiment of the invention the flat rod is preferablymade of a light metal or a light metal alloy, in particular it is madeof aluminium or an aluminium alloy.

[0024] The object of the invention, which in all foregoing embodimentsof the invention is called “fastening means” can also be a so calledclip, in particular, for fastening of clothing strips onto flat rods(revolving flat or stationary flat rods) of the card. In addition, theclothing strips can be furnished with an allsteel clothing (saw toothtype clothing). The object of the invention is not limited to theapplication in flat rods of the card. It can also serve in particular asfastening means for other carding segments with other clothing types(carding segments of the card, such as those of other blow roommachines, in particular cleaners). The object of the invention issuitable preferentially also as fastening means for carding segmentswith all steel clothing. The fastening means according to the inventioncan therefore also be applied in other carding segments in the card orin a cleaner of the blow room. Together with the card go the cardingsegments in the pre-carding zone or recarding zone of the cylinder, orthe carding segments at the licker-in. With cleaners the fastening meanscan be applied with stationary carding segments. If the fastening meansis a clip, then it can be made of sheet metal, preferably of steel.

[0025] If the sliding means between the contact surfaces of fasteningmeans and flat rod is being realised as gliding layer with a lowcoefficient of friction, then the gliding layer can be applied in theform of a coating, in particular a plastic coating, on the fasteningmeans and/or on the flat rod. The application of the coating can alsotake place later.

[0026] In a preferred embodiment the coating is applied only on thecontact surfaces between the fastening means and the flat rod.

[0027] In a further preferred embodiment of the invention the fasteningmeans has teeth, which are stable enough to be entered or punched intothe fabric and/or plastic layers of the clothing strips. This featureapplies in particular to fastening means which are not made of steel orsheet metal, but for example of aluminium or consist of anothermaterial. Such fastening means according to the invention are inparticular suitable for the fastening of clothing strips on machinecomponents of the card.

[0028] For the fastening of the clothing strips on the flat rodspreferably at least two fastening means are applied according to theinvention.

[0029] The present invention is described in the following figures byway of examples, wherein shows:

[0030]FIG. 1, a flat rod with clips according to the state of the knownart.

[0031]FIG. 2, a fastening means according to the third idea ofembodiment of the invention.

[0032]FIG. 3, a variation according to the third idea of embodiment ofthe invention.

[0033]FIG. 4, a fastening means according to the fifth embodiment of theinvention with sliding means.

[0034]FIG. 5, a further fastening means according to the invention

[0035] The flat rod in FIG. 1 was already described further above.Therefore, there is no need for further explanation. The clips 1 aremanufactured according to the state of the art of sheet metal or steeland have a wall thickness of 0,5 mm. The flat rod 3 is made of a lightmetal or a light metal alloy. This combination has the above-describeddisadvantages.

[0036] In FIG. 2 a fastening means according to the third idea ofembodiment of the invention is shown (in two views). The fastening means9 according to the invention is more flexible in its longitudinaldirection 10 than in its transverse direction 11. This characteristicwas achieved at the fastening means 9 by way of its structural design.It has groove shaped predetermined weak points 12 at regular spaces inits longitudinal direction 10. The wall thickness is reduced at thesepoints, so that the fastening means 9 has an overall reduced rigidity inlongitudinal direction 10 and thus a higher elasticity. By thisstructural design the clamping force in cross direction 11 is hardlyreduced and the elasticity of the fastening means 9 is onlyinsignificantly increased.

[0037] The FIG. 3 shows a further variation of the third idea ofembodiment according to the invention, likewise in two views. Here alsopredetermined weak points 12 in the form of punched material are workedinto the fastening means 13. Thus the fastening means receive adirection-controlled elasticity and/or rigidity, and thus the fasteningmeans 13 becomes lengthwise flexible. In cross direction 11, however, itkeeps the required rigidity.

[0038] The FIG. 4 shows a flat rod 3.1 with a clothing strip 2, which isattached by two fastening means 16 according to the fifth embodiment ofthe invention.

[0039] Between the contact surfaces of fastening means 15 and the flatrod 3.1 sliding means 14 are attached. In this embodiment the twofastening means 15 also have teeth 4, which engage in the clothing strip2 of the fabric layer. The sliding means 14 are here only to beunderstood as schematic illustrations. They permit the flat rod 3.1 andthe fastening means 15 to move relatively to each other (in viewingdirection, i.e. in longitudinal direction of the flat rod 3.1), inparticular to expand relatively to each other at a temperature rise. Assliding means 14 gliding layers could for example be applied, which havea low coefficient of friction. The sliding means 14 can be applied bothon the fastening means 15 and/or on the flat rod 3.1. The sliding means14 can only be attached on the contact surfaces (as shown), or extendbeyond one and/or the other component (fastening means 15 or flat rod3.1) covering it entirely or partly (not shown). For example thefastening means 15 could be completely surrounded and/or coated by thesliding means 14. The illustrated sliding means 14 can also be a plasticcoating (or a silicone layer).

[0040] The FIG. 5 shows a detail of a fastening means 16 according tothe invention. Thereby the fastening means 16 is shown in twoconditions. The illustration on the left shows the fastening means 16 inthe unbent condition, one sees in particular the teeth 4.

[0041] According to one design of the embodiment according to theinvention, the fastening means 16 can comprise a wall thickness d, whichis thinner than 0.4 mm preferably thinner than 0.3 mm.

[0042] The illustration on the right shows the fastening means 16 in theform as it is applied in mounted condition (without flat rod or clothingstrip). One sees the way the teeth 4 are pointing upward, during anormal assembly these are punched and/or pressed into the fabric layersof the clothing strip (see teeth of FIG. 4). The teeth 4 according tothe invention are designed in such a manner (e.g. by their form anddimensions) that they are stable enough in order to be engaged in thefabrics and/or plastic layers of the clothing strips.

[0043] The fastening means according to the invention consistspreferably of a material which possesses the same coefficient ofelongation as light metal or light metal alloys, under whichparticularly is to be understood aluminium or aluminium alloys. Thefastening means consists in particular of a material which possesses thesame coefficient of elongation as the material of which the flat rodsare manufactured, whereby these are preferably produced of light metalor light metal alloys.

[0044] The invention also concerns the use of fastening means on theflat rods, made of light metal, for the fastening of clothing strips.

[0045] With the expression “fastening means” clips for the fastening ofclothing are to be understood in particular. These clothing could beflexible clothing, in particular so-called clothing strips, but alsoallsteel clothing, e.g. saw tooth clothing. Preferably the fasteningmeans according to the invention are applied for the flat rods of thecard They are, however, not limited to this application. The fasteningmeans according to the invention can in particular also serve for thefastening of other carding segments, in particular for stationarycarding segments in the pre-carding zone and in the re-carding zone ofthe card, as well as at its licker-in and at cleaners in the blow room.The fastening means according to the invention can be used for examplefor applications according to the disclosures CH 659,832, CH 654,341, CH655,521 in place of the conventional clips or clips described there, inparticular for holding allsteel clothing and so called card clothing.

[0046] The invention is not limited to the possibilities and embodimentsexplicitly being specified. These variations are rather meant assuggestions for the specialist for the realisation of the idea of theinvention in a most favourable manner. From the described forms ofembodiments therefore further favourable applications and combinationsare easily derivable, which likewise reflect the idea of the inventionand which are to be protected by this application.

[0047] In the following claims some of the features, having beendisclosed in the above description, are being claimed in a combinedform. It may, however, also be possible to claim some of the features ofthe description individually.

1. Fastening means for the fastening of clothing strips (2) on flat rods(3) made of light metal or light metal alloys, characterized in that thefastening means consists of a material which possesses the samecoefficient of elongation as the flat rod (3), preferentially thefastening means consists of the same material as the flat rod (3). 2.Fastening means for the fastening of clothing strips (2) on flat rods,characterized in that the fastening means consists of aluminium, or analuminium alloy, or another light metal or another light metal alloy. 3.Fastening means according to claim 2, characterized in that the flatrods (3) consists of light metal or light metal alloys, consists inparticular of aluminium or an aluminium alloy.
 4. Fastening means forthe fastening of clothing strips (2) on flat rods, characterized in thatthe fastening means (9, 13) is more flexible in its longitudinaldirection than in its cross direction.
 5. Fastening means according toclaim 4, characterized in that the fastening means (9, 13) in its layoutis furnished with predetermined weak points (12, 12.1).
 6. Fasteningmeans according to claim 5, characterized in that the predetermined weakpoints (12, 12.1) are designed in such a manner, that the fasteningmeans (9, 13) comprises, depending on the direction, differing values ofelasticity.
 7. Fastening means according to claim 5, characterized inthat the predetermined weak points (12, 12.1) are applied in thefastening means (9, 13) by way of punched-out material.
 8. Fasteningmeans for the fastening of clothing strips on flat rods, characterizedin that the fastening means (16) have a wall thickness which is lessthan 0.4 preferably less than 0.3 mm.
 9. Fastening means for thepositive fastening of clothing strips (2) on flat rods, characterized inthat a sliding means (14) is applied between the contact surfaces of thefastening means (15) and the flat rod (3.1).
 10. Fastening meansaccording to claim 9, characterized in that the sliding means (14) isarranged in such a manner that, at temperature rise, it allows thefastening means (15) and the flat rod (3.1) to move along side the flatrod (3.1) relatively too each other.
 11. Fastening means according toclaims 9 to 10, characterized in that the sliding means (14) between thecontact surfaces of the fastening means (15) and flat rod (3.1) is agliding layer (14) with a low coefficient of friction.
 12. Fasteningmeans according to claim 1 to 11, characterized in that the fasteningmeans is a clip (9, 13, 15, 16).
 13. Fastening means according to claim12, characterized in that the fastening means is a clip (9, 13, 15, 16)which is manufactured of sheet metal, preferentially of steel. 14.Fastening means according to claim 9, characterized in that the flat rod(3, 3.1) consists of a light metal or a light metal alloy, in particularof aluminium or of an aluminium alloy.
 15. Fastening means according toclaim 11, characterized in that the gliding layer (14) is subsequentlyapplied in the form of a coating, in particular a plastic coating, onthe fastening means (15) and/or on the flat rod (3.1).
 16. Fasteningmeans according to claim 15, characterized in that the coating (14) isapplied only to contact surfaces between the fastening means (15) andflat rod (3.1).
 17. Fastening means according to the preceding claims,characterized in that the fastening means (9, 13, 15, 16) comprisesteeth (4), which are stable enough in order to be inserted or punchedinto the fabric and/or plastic layers of the clothing strip (2). 18.Fastening means according to the preceding claims, characterized in thatthe fastening means (9, 13, 15, 16) is suitable for the fastening ofclothing strips (2) onto mechanical components of a card.
 19. Fasteningmeans according to the preceding claims, characterized in that for thefastening of the clothing strips (2) on the flat rods (3, 3.1), in eachcase at least two fastening means (9, 13, 15, 16) are used.